Ontogenia craniana de Salamandra salamandra e sua correlação com a transição peixe-tetrápode

Abstract

Salamanders are widely used as a model to understand evolutionary steps in tetrapod’s water-to-land transition. In recent decades, the skull has proved to be a particularly promising structure for understanding this process. The role of metamorphosis in salamander development and origin of other ontogenies in the group may contribute to understanding the evolutionary contingencies that allowed the first tetrapods to walk on earth. In this sense, the present work seeks to understand its use as a model through the cranial anatomy of an ontogenetic series of Salamandra salamandra, elaborating a dialogue between the development before and after the metamorphosis with the fish-tetrapod transition. The anatomical changes that occur throughout ontogeny are directly related to the transition from the aquatic to the terrestrial environment, constricting the way that bone elements are organized and ossified. Although the anatomical elements of the skull allow inferences about this evolutionary event, such as the similarity between the dorsoventral flattening that occurs between pre- and post-metamorphic stages and the same happened with tetrapodomorphs, the dialogue depends on ecology as the means to correlate metamorphosis and the exit of waters consistent with the modern vision of evolution.